Medicaid Expansion Helped Improve Survival for People with HER2 Positive Breast Cancer

New research published in JNCCN—Journal of the National Comprehensive Cancer Network found that people with newly-diagnosed hormone receptor (HR)-negative, human epidermal growth factor receptor 2 (HER2)-positive breast cancer were more likely to receive timely, guideline-concordant treatment and have longer survival in states that participate in Medicaid expansion under the Affordable Care Act (ACA).

A team of researchers—led by the American Cancer Society (ACS), and including Kathryn J. Ruddy, MD, MPH, of the Mayo Clinic Comprehensive Cancer Center, a former NCCN Foundation Young Investigator Award recipient—used data from the National Cancer Database (NCDB) to review results for women across the United States, age 18-62, who were diagnosed with this type of breast cancer between 2010 and 2018. 19,248 of the patients lived in Medicaid expansion states, while 12,153 resided in non-expansion locations. In the expansion states, the 2-year survival rate increased from the 2010 baseline rate of 93.9% to 95.0% across the study period. However, in the non-expansion states, 2-year survival declined slightly from 94.0% to 93.9%. The biggest difference was seen in patients with Stage III disease.

“Expanding Medicaid to the 10 states that have yet to do so can help ensure that more patients with cancer benefit from life-saving treatments,” said lead researcher Kewei Sylvia Shi, MPH, Surveillance and Health Equity Science, American Cancer Society. “It’s crucial to increase access to oncology services, expand insurance coverage, and streamline diagnostic and referral processes. Stage III cancer represents a critical point in disease presentation and can further progress and become incurable if undertreated. Having health insurance coverage will make it more likely for these patients to receive timely and comprehensive access to life-saving therapies, have better medication adherence, and complete treatment, which leads to better survival outcomes.”

HR-negative, HER2-positive breast cancer is an aggressive subtype that accounts for approximately 5%of all breast cancer diagnoses. This is the first study to focus on the impact of Medicaid expansion on that specific population.

The study found that treatment according to recommendations from evidence-based, expert consensus driven clinical practice guidelines—such as the National Comprehensive Cancer Network (NCCN) Clinical Practice Guidelines in Oncology (NCCN Guidelines )— was more likely to begin within 90 days from diagnosis in the expansion states.

“This study reinforces the important role Medicaid expansion plays in ensuring that women newly diagnosed with HR-negative, HER2-positive breast cancer have equitable access to the healthcare services they need—especially when prognosis depends on access to treatment,” said Millicent Gorham, CEO of the Alliance for Women’s Health and Prevention, who was not involved in this research. “Breast cancer is far too common, and rates are increasing among younger women, making it critical that policymakers also prioritize women’s access to preventive health screenings and appropriate treatments.”